U.S. patent application number 13/607634 was filed with the patent office on 2013-08-29 for solid oxide fuel cell and manufacturing method thereof.
The applicant listed for this patent is Gyu-Jong Bae, Sang-Jun Kong, Tae-Ho Kwon, Young-Sun Kwon, Kwang-Jin Park, Hyun Soh, Duk-Hyoung Yoon. Invention is credited to Gyu-Jong Bae, Sang-Jun Kong, Tae-Ho Kwon, Young-Sun Kwon, Kwang-Jin Park, Hyun Soh, Duk-Hyoung Yoon.
Application Number | 20130224630 13/607634 |
Document ID | / |
Family ID | 49003223 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130224630 |
Kind Code |
A1 |
Kwon; Young-Sun ; et
al. |
August 29, 2013 |
SOLID OXIDE FUEL CELL AND MANUFACTURING METHOD THEREOF
Abstract
A solid oxide fuel cell and a manufacturing method thereof
includes a unit cell and a cell coupling member. The unit cell
includes a first electrode layer, an electrolyte layer surrounding
an outer peripheral surface of the first electrode layer, and a
second electrode layer surrounding the electrolyte layer so that
one end portion of the electrolyte layer is exposed. The cell
coupling member is coupled to the unit cell and includes a coupling
member. A sealing member including at least two layers having
different porosities is coated on at least one portion of the
coupling member to seal the unit cell and the cell coupling
member.
Inventors: |
Kwon; Young-Sun; (Yongin-si,
KR) ; Kong; Sang-Jun; (Yongin-si, KR) ; Soh;
Hyun; (Yongin-si, KR) ; Park; Kwang-Jin;
(Yongin-si, KR) ; Bae; Gyu-Jong; (Yongin-si,
KR) ; Yoon; Duk-Hyoung; (Yongin-si, KR) ;
Kwon; Tae-Ho; (Yongin-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kwon; Young-Sun
Kong; Sang-Jun
Soh; Hyun
Park; Kwang-Jin
Bae; Gyu-Jong
Yoon; Duk-Hyoung
Kwon; Tae-Ho |
Yongin-si
Yongin-si
Yongin-si
Yongin-si
Yongin-si
Yongin-si
Yongin-si |
|
KR
KR
KR
KR
KR
KR
KR |
|
|
Family ID: |
49003223 |
Appl. No.: |
13/607634 |
Filed: |
September 7, 2012 |
Current U.S.
Class: |
429/509 ;
156/293; 156/60; 429/508 |
Current CPC
Class: |
H01M 8/04201 20130101;
Y10T 156/10 20150115; H01M 8/004 20130101; Y02E 60/50 20130101;
H01M 2008/1293 20130101; H01M 8/0282 20130101; Y02P 70/50
20151101 |
Class at
Publication: |
429/509 ;
429/508; 156/60; 156/293 |
International
Class: |
H01M 2/08 20060101
H01M002/08; B32B 37/12 20060101 B32B037/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2012 |
KR |
10-2012-0018446 |
Claims
1. A solid oxide fuel cell, comprising: a unit cell comprising a
first electrode layer, an electrolyte layer surrounding an outer
peripheral surface of the first electrode layer, and a second
electrode layer surrounding the electrolyte layer so that one end
portion of the electrolyte layer is exposed; and a cell coupling
member coupled to the unit cell, the cell coupling member
comprising a coupling member; and a sealing member on at least one
portion of the coupling member, the sealing member comprising at
least two layers having different porosities, the sealing member
being configured to seal the cell coupling member and the unit
cell.
2. The solid oxide fuel cell according to claim 1, wherein the
sealing member comprises a first sealing member and a second
sealing member, and the porosity of the first sealing member is
greater than that of the second sealing member.
3. The solid oxide fuel cell according to claim 2, wherein the
porosity of the first sealing member is 10% to 25%.
4. The solid oxide fuel cell according to claim 2, wherein the
porosity of the second sealing member is greater than 0% to
15%.
5. The solid oxide fuel cell according to claim 2, wherein the
viscosity of the second sealing member, prior to drying, is greater
than that of the first sealing member, prior to drying.
6. The solid oxide fuel cell according to claim 5, wherein the
viscosity of the second sealing member, prior to drying, is 10% or
more than that of the first sealing member.
7. The solid oxide fuel cell according to claim 1, wherein the
sealing member comprises a ceramic material.
8. The solid oxide fuel cell according to claim 1, wherein the cell
coupling member comprises a flow path tube inserted into the unit
cell and configured to form a flow path from the inside of the unit
cell to the outside of the unit cell, and the coupling member
comprises a first coupling member at an outside of the flow path
tube and a second coupling member connected to the first coupling
member, the first coupling member being configured to receive the
end portion of the unit cell between the second coupling member and
the flow path tube and the second coupling member defining the
insertion depth of the electrolyte layer and the first electrode
layer into the cell coupling member.
9. The solid oxide fuel cell according to claim 8, wherein the
sealing member comprises a first sealing member and a second
sealing member, and the first sealing member is on a surface of the
first coupling member to seal a gap between the end portion of the
unit cell and the first coupling member.
10. The solid oxide fuel cell according to claim 8, wherein the
sealing member comprises a first sealing member and a second
sealing member and the second sealing member is on an inner
circumferential surface of the second coupling member to seal a gap
between a side portion of the unit cell and the second coupling
member.
11. A method of manufacturing a solid oxide fuel cell, the method
comprising: providing a unit cell comprising a first electrode
layer, an electrolyte layer surrounding an outer peripheral surface
of the first electrode layer, and a second electrode layer
surrounding the electrolyte layer so that one end portion of the
electrolyte layer is exposed; providing a cell coupling member
comprising a coupling member; and sealing the unit cell and the
cell coupling member by coating a sealing member comprising at
least two layers having different porosities on at least one
portion of the coupling member and drying the sealing member.
12. The method according to claim 11, wherein, in the providing the
cell coupling member, the cell coupling member comprises a flow
path tube and the coupling member comprises a first coupling member
and a second coupling member, the first coupling member being at an
outside of the flow path tube and configured to receive the end
portion of the unit cell between the second coupling member and the
flow path tube and the second coupling member defining the
insertion depth of the electrolyte layer and the first electrode
layer into the cell coupling member, and wherein the sealing the
unit cell and the cell coupling member comprises inserting the flow
path tube into the inside of the unit cell to form a flow path from
the inside to the outside of the unit cell.
13. The method according to claim 12, wherein the sealing member
comprises a first sealing member and a second sealing member, and
the first sealing member is coated on a surface of the first
coupling member and then pressed and dried to seal a gap between
the end portion of the unit cell and the first coupling member.
14. The method according to claim 12, wherein sealing member
comprises a first sealing member and a second sealing member, and
the second sealing member is coated on an inner circumferential
surface of the second coupling member and then pressed and dried to
seal a gap between a side portion of the unit cell and the second
coupling member.
15. The method according to claim 11, wherein the sealing member
comprises a first sealing member and a second sealing member, and
the porosity of the second sealing member is less than that of the
first sealing member.
16. The method according to claim 15, wherein the porosity of the
first sealing member is 10% to 25%.
17. The method according to claim 15, wherein the porosity of the
second sealing member is greater than 0% to 15%.
18. The method according to claim 15, wherein the second sealing
member is formed by being pressed and dried at room temperature.
Description
RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2012-0018446, filed in the Korean
Intellectual Property Office on Feb. 23, 2012, the entire content
of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] An aspect of the present invention relates to a fuel cell
and a manufacturing method thereof.
[0004] 2. Description of the Related Art
[0005] Fuel cells are a high-efficiency, clean generation
technology for directly converting hydrogen and oxygen into
electric energy through an electrochemical reaction. Here, the
hydrogen is contained in a hydrocarbon-based material such as
natural gas, coal gas, or methanol, and the oxygen is contained in
the air. Such fuel cells are classified into alkaline fuel cells,
phosphoric acid fuel cells, molten carbonate fuel cells, solid
oxide fuel cells, and polymer electrolyte membrane fuel cells,
depending on the type of electrolyte used.
[0006] Among these fuel cells, the solid oxide fuel cell is a fuel
cell operated at a high temperature of about 600 to 1000.degree. C.
Solid oxide fuel cells are widely used because the position of the
electrolyte is relatively easily controlled, there is little or no
concern about the exhaustion of fuel, and the lifetime of the
material is long, compared with various types of conventional fuel
cells.
[0007] In solid oxide fuel cells, the inside and outside of a unit
cell are different electrodes from each other, and therefore,
different kinds of fuels are supplied to the electrodes,
respectively. When a leak occurs in a sealing portion due to the
lack of sealing between the unit cell and a cell coupling member,
the temperature of the cell is increased by mixing and igniting
both the fuels at a high temperature, and accordingly, the
deterioration of the cell is accelerated. Therefore, the durability
of the solid oxide fuel cell may be reduced.
SUMMARY
[0008] Aspects of embodiments of the present invention provide a
solid oxide fuel cell and a manufacturing method thereof, in which
a multi-layered sealing member, different layers having different
porosities, is formed between a cell coupling member and a unit
cell, so that the cell coupling member and the unit cell can be
closely sealed.
[0009] According to an embodiment of the present invention, a solid
oxide fuel cell includes a unit cell, a cell coupling member, and a
sealing member. The unit cell includes a first electrode layer, an
electrolyte layer surrounding an outer peripheral surface of the
first electrode layer, and a second electrode layer surrounding the
electrolyte layer so that one end portion of the electrolyte layer
is exposed. The cell coupling member includes a coupling member,
and the cell coupling member is coupled to the unit cell. The
sealing member is on at least one portion of the coupling member,
and the sealing member includes at least two layers having
different porosities, and the sealing member is configured to seal
the cell coupling member and the unit cell.
[0010] The sealing member may include a first sealing member and a
second sealing member, and the porosity of the first sealing member
may be greater than that of the second sealing member. The porosity
of the first sealing member may be 10% to 25%. The porosity of the
second sealing member may be greater than 0% to 15%. The viscosity
of the second sealing member, prior to drying, may be greater than
that of the first sealing member, prior to drying. The viscosity of
the second sealing member, prior to drying, may be 10% or more than
that of the first sealing member.
[0011] The sealing member may include a ceramic material.
[0012] The cell coupling member may include a flow path tube
inserted into the unit cell that is configured to form a flow path
from the inside of the unit cell to the outside of the unit cell.
The coupling member of the cell coupling member may include a first
coupling member at an outside of the flow path tube and a second
coupling member connected to the first coupling member. The first
coupling member may be configured to receive the end portion of the
unit cell between the second coupling member and the flow path
tube, and the second coupling member may define the insertion depth
of the electrolyte layer and the first electrode layer into the
cell coupling member.
[0013] The sealing member may include a first sealing member and a
second sealing member, and the first sealing member may be on a
surface of the first coupling member to seal a gap between the end
portion of the unit cell and the first coupling member. The second
sealing member may be on an inner circumferential surface of the
second coupling member to seal a gap between a side portion of the
unit cell and the second coupling member.
[0014] According to an embodiment of the present invention, a
manufacturing method of a solid oxide fuel cell includes providing
a unit cell, providing a cell coupling member, and sealing the unit
cell and the cell coupling member. The providing a unit cell
includes providing a unit cell having a first electrode layer, an
electrolyte layer surrounding an outer peripheral surface of the
first electrode layer, and a second electrode layer surrounding the
electrolyte layer so that one end portion of the electrolyte layer
is exposed. The providing a cell coupling member includes providing
a cell coupling member including a coupling member. The sealing the
unit cell and the cell coupling member includes sealing the unit
cell and the cell coupling member by coating a sealing member,
having at least two layers having different porosities, on at least
one portion of the coupling member and drying the sealing
member.
[0015] The providing the cell coupling member may include providing
a cell coupling member including a flow path tube. The coupling
member may include a first coupling member and a second coupling
member, the first coupling member being at an outside of the flow
path tube and configured to receive the end portion of the unit
cell between the second coupling member and the flow path tube, and
the second coupling member defining the insertion depth of the
electrolyte layer and the first electrode layer into the cell
coupling member. The sealing the cell coupling member to the unit
cell may include inserting the flow path tube into the inside of
the unit cell to form a flow path from the inside to the outside of
the unit cell.
[0016] The sealing member may include a first sealing member and a
second sealing member. The first sealing member may be coated on a
surface of the first coupling member and then pressed and dried to
seal a gap between the end portion of the unit cell and the first
coupling member. The second sealing member may be coated on an
inner circumferential surface of the second coupling member and
then pressed and dried to seal a gap between a side portion of the
unit cell and the second coupling member.
[0017] The porosity of the second sealing member may be less than
that of the first sealing member. The porosity of the first sealing
member may be 10% to 25%. The porosity of the second sealing member
may be greater than 0% to 15%. The second sealing member may be
formed by being pressed and dried at room temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, together with the specification,
illustrate exemplary embodiments of the present invention, and,
together with the description, explain principles of embodiments of
the present invention.
[0019] FIG. 1 is a partial perspective view showing a unit cell and
a cell coupling member according to an embodiment of the present
invention.
[0020] FIG. 2 is a cross-sectional view showing the unit cell and
the cell coupling member according to one embodiment of the present
invention.
[0021] FIG. 3 is a cross-sectional view showing the unit cell and
the cell coupling member coupled to each other according to one
embodiment of the present invention.
[0022] FIG. 4 is an enlarged view showing portion A of FIG. 3.
[0023] FIGS. 5A and 5B are scanning electron microscope (SEM)
photographs respectively showing first and second sealing members
constituting a double-layered sealing member according to the
embodiment of the present invention.
[0024] FIG. 6 is a flowchart illustrating a manufacturing method of
a solid oxide fuel cell according to an embodiment of the present
invention.
DETAILED DESCRIPTION
[0025] In the following detailed description, only certain
exemplary embodiments of the present invention have been shown and
described, simply by way of illustration. As those skilled in the
art would realize, the described embodiments may be modified in
various different ways, all without departing from the spirit or
scope of the present invention. Accordingly, the drawings and
description are to be regarded as illustrative in nature and not
restrictive.
[0026] In addition, when an element is referred to as being "on"
another element, it may be directly on the another element or may
be indirectly on the another element with one or more intervening
elements interposed therebetween. Also, when an element is referred
to as being "connected to" another element, it may be directly
connected (or coupled) to the another element or be indirectly
connected (or coupled) to the another element with one or more
intervening elements interposed therebetween.
[0027] Hereinafter, like reference numerals refer to like elements.
In the drawings, the thickness or size of layers may be exaggerated
for clarity and are not necessarily drawn to scale.
[0028] FIG. 1 is a partial perspective view showing a unit cell and
a cell coupling member according to an embodiment of the present
invention. FIG. 2 is a cross-sectional view showing the unit cell
and the cell coupling member according to one embodiment of the
present invention. FIG. 3 is a cross-sectional view showing the
unit cell and the cell coupling member coupled to each other
according to one embodiment of the present invention. FIG. 4 is an
enlarged view showing portion A of FIG. 3. FIGS. 5A and 5B are
scanning electron microscope (SEM) photographs respectively showing
first and second sealing members constituting a double-layered
sealing member according to the embodiment of the present
invention.
[0029] Referring to FIGS. 1 to 3, the solid oxide fuel cell 1
according to this embodiment includes a unit cell 100 and a cell
coupling member 300. The unit cell 100 includes a first electrode
layer 110, an electrolyte layer 120 surrounding the outer
peripheral surface (e.g., the outer circumferential surface) of the
first electrode layer 110, and a second electrode layer 130
surrounding the electrolyte layer 120 so that one end portion of
the electrolyte layer 120 is exposed. That is, as shown in FIG. 2,
the bottom end portion of the electrolyte layer 120 and the first
electrode layer 110 extend beyond the bottom end portion of the
second electrode layer 130. The cell coupling member 300 includes a
coupling member 303, and is coupled to the unit cell 100. When the
cell coupling member 300 is coupled to the unit cell 100, a flow
path (e.g., a continuous flow path) from the inside to the outside
of the unit cell 100 is formed. A sealing member composed of two or
more (i.e., at least two) layers having different porosities is
coated on at least one portion of the coupling member 303 so that
the unit cell 100 and the cell coupling member 300 are sealed
together. That is, the sealing member seals a joint between the
unit cell 100 and the cell coupling member 300.
[0030] The unit cell 100 is formed in the shape of a cylinder that
is hollow in the center. The unit cell 100 includes the first
electrode layer 110, the electrolyte layer 120 and the second
electrode layer 130, sequentially formed from the inside to the
outside of the unit cell 100. Here, the electrolyte layer 120 is
formed to surround the outer peripheral surface (e.g., the outer
circumferential surface) of the first electrode layer 110, and the
second electrode layer 130 is formed to surround the electrolyte
layer 120 while exposing the one end portion of the electrolyte
layer 120. According to the type of the fuel cell, the first
electrode layer 110 may be an anode or a cathode, and the second
electrode layer 130 may be the other of the cathode or the anode.
In one embodiment, the first electrode layer 110 is an anode and
the second electrode layer 130 is a cathode.
[0031] The cell coupling member 300 is configured to allow hydrogen
gas and external air not to be mixed together (i.e., to maintain
the separation of hydrogen gas and external air), and includes a
flow path tube 301 and the coupling member 303. Here, the hydrogen
gas and external air are respectively supplied to the inside and
outside of the unit cell 100. One end of the flow path tube 301 is
inserted into the unit cell 100 through an opening at the bottom
end of the unit cell 100. The flow path tube 301 is connected to an
internal space of the unit cell 100 so as to form a flow path, and
functions to transfer fuel or air to or from the unit cell 100 to
another component of the fuel cell. The coupling member 303
includes a first coupling member 303a serving as an accommodating
or receiving portion 302 and a second coupling member 303b defining
the depth that the electrolyte layer 120 and the first electrode
layer 110 are inserted into the cell coupling member 300.
[0032] The first coupling member 303a has a diameter greater than
that of the flow path tube 301 at the outside of the flow path tube
301 so as to form a space in which the end portion of the unit cell
100 is accommodated. The second coupling member 303b is connected
to the first coupling member 303a to support the first coupling
member 303a, and defines the insertion depth of the electrolyte
layer 120 and the first electrode layer 110 when the unit cell 100
is inserted into the receiving portion 302. In one embodiment, the
flow path tube 301, the first coupling member 303a and the second
coupling member 303b are integrally formed so as to improve sealing
performance, durability and the like.
[0033] The sealing member 200 composed of two or more layers having
different porosities is coated on a portion of the coupling member
303 in the receiving portion 302 so that the unit cell 100 and the
cell coupling member 300 are sealed together. The sealing member
200 may be made of a ceramic material. If the sealing member 200 is
pressed and then dried or sintered, the unit cell 100 and the cell
coupling member 300 can be sealed together. Specifically, a first
sealing member 201 is formed on a surface of the first coupling
member 303a so as to seal a gap between the end portion of the unit
cell 100 and the first coupling member 303a, and a second sealing
member 202 is formed on the inner circumferential surface of the
second coupling member 303b so as to seal a gap between an outer
side portion of the unit cell 100 and the second coupling member
303b.
[0034] Accordingly, as shown in FIG. 4, a double layer sealing
member 200 composed of the first and second sealing members 201 and
202 is formed on a portion of the coupling member 303. According to
this embodiment, the first sealing member 201 has a porosity
greater than that of the second sealing member 202, and the first
sealing member 201 has a porosity of 10% or more and 25% or less,
and the second sealing member 202 has a porosity of more than 0%
and 15% or less. As described above, the double layered sealing
member 200 is formed by coating the second sealing member 202 (see
FIG. 5B), having a porosity smaller than that of the first sealing
member 201, on the first sealing member 201 (see FIG. 5A), having a
porosity greater than that of the second sealing member 202, so
that it is possible to reduce gas leakage in the inside of the unit
cell 100. Meanwhile, the first sealing member 201 has a lower
viscosity than the second sealing member 202 (prior to drying). For
example, the first sealing member 201 may have a viscosity of 700
cp or more and 80000 cp or less prior to drying, and the second
sealing member 202 may have a viscosity 10% greater than that of
the first sealing member 201 prior to drying. Because the first
sealing member 201 has a relatively low viscosity prior to drying,
its workability is good. Because the second sealing member 201 has
a relatively high viscosity prior to drying, its compactness (e.g.,
its density) is high. Accordingly, it is possible to reduce the gas
leakage.
[0035] An embodiment of the present invention will be described
with reference to Examples 1 and 2 and Comparative Examples 1 and
2, and FIG. 6, which is a flowchart illustrating a manufacturing
method of a solid oxide fuel cell. The unit cells, cell coupling
members, and sealing members of Examples 1 and 2 and Comparative
Examples 1 and 2 were formed and assembled as follows.
[0036] First, a unit cell 100 is manufactured in the shape of a
hollow cylinder (S1). The unit cell 100 includes a first electrode
layer 110, an electrolyte layer 120 and a second electrode layer
130, sequentially formed from the inside to the outside of the unit
cell 100. Here, the electrolyte layer 120 is formed to surround the
outer circumferential surface of the first electrode layer 110, and
the second electrode layer 130 is formed to surround the
electrolyte layer 120 while exposing an end portion of the
electrolyte layer 120.
[0037] Next, a cell coupling member 300 is prepared (S2). The cell
coupling member 300 includes a flow path tube 301 and a coupling
member 303, which are integrally formed. The flow path tube 301 is
connected to an internal space of the unit cell 100 so as to form a
flow path, and transfer fuel or air to another component of the
unit cell 100. The coupling member 303 includes a first coupling
member 303a forming a receiving portion 302 and a second coupling
member 303b defining the insertion depth of the electrolyte layer
120 and the first electrode layer 110.
[0038] Finally, the unit cell 100 and the cell coupling member 300
are sealed by forming a sealing member 200 composed of two or more
layers, having different porosities, on at least one portion of the
coupling member 303 (S3).
[0039] The sealing of the unit cell 100 and the cell coupling
member 300 using the sealing member 200 (S3) will be described in
detail with reference to FIGS. 2 to 4.
[0040] First, as shown in FIG. 2, the first sealing member 201 is
coated on the surface of the first coupling member 303a. Next, the
one end portion of the unit cell 100 is mounted in the
accommodating or receiving portion 302 of the cell coupling member
300, and the one end portion of the unit cell 100 and the cell
coupling member 300 are then coupled by pressing and drying the
first sealing member 201 at a normal temperature (e.g., room
temperature or about 20 to 25.degree. C.) for 24 hours. For
example, the first sealing member 201 may be completely dried in
terms of durability. Because the first sealing member 201 has a
relatively low viscosity of about 20000 cp, its workability is
good. Next, as shown in FIG. 3, the second sealing member 202 is
coated on the inner circumferential surface of the second coupling
member 303b, and the side portion of the unit cell 100 and the cell
coupling member 300 are then coupled by pressing and drying the
second sealing member 202 at a normal temperature (e.g., room
temperature) for 4 hours. Finally, the first and second sealing
members 201 and 202 are further dried by sintering the unit cell
100 coupled to the cell coupling member 300 at 300.degree. C. for 2
hours. Accordingly, the solid oxide fuel cell 1 is completed.
According to the configuration described above, the second sealing
member 202 fills a gap (e.g., a fine gap) between the one end
portion of the unit cell 100 and the cell coupling member 300 so
that the solid oxide fuel cell 1 can be tightly sealed. As shown in
FIG. 4, the double-layered sealing member 200 composed of the first
and second sealing members 201 and 202 is formed on at least one
portion of the coupling member 303.
[0041] Each of Examples 1-2 and Comparative Examples 1-2 included
different sealing members. As described in Table 1, the first
sealing member 201 according to Example 1 and the first sealing
member 201 according to Example 2 had porosities of 24.2% and
20.5%, respectively. The second sealing member 202 according to
Example 1 and the second sealing member 202 according to Example 2
had porosities of 13.1% and 2.9%, respectively. The sealing members
according to Comparative Examples 1 and 2 were formed as single
layers having porosities of 21.6% and 1.5%, respectively.
[0042] The gas leakage amount for the unit cell 100 of each of the
Examples and Comparative Examples were measured. The method of
measuring gas leakage amount will be briefly described. First, a
tube of a gas leakage measuring device was connected to a portion
at which the solid oxide fuel cell and a pipe are connected. The
pipe is connected to the flow path tube. Next, the inside of the
solid oxide fuel cell is vacuum-evacuated and then filled with
helium (He) gas. When measuring the gas leakage amount, it is
important to remove the helium gas from around the gas leakage
measuring device so that the only gas detected is that leaked from
the solid oxide fuel cell.
[0043] The measured results are described in Table 1. In the
"Result" column, an "o" indicates that a seal was formed and there
was relatively little leakage, while an "x" indicates that a seal
was not formed and/or there was more significant leakage.
TABLE-US-00001 TABLE 1 Porosity (%) Gas First Second leakage
sealing sealing amount (L/ member member cm.sup.2 s atm) Result
Remarks Example 1 24.2 13.1 4.0 .times. 10.sup.-6 .smallcircle.
Example 2 20.5 2.9 8.0 .times. 10.sup.-8 .smallcircle. Comparative
21.6 -- 4.0 .times. 10.sup.-4 x Example 1 Comparative 1.5 -- 6.0
.times. 10.sup.-5 x Fail to form Example 2 sealing member
[0044] As shown in Table 1, in Examples 1 and 2 in which the
double-layered sealing member 200 was formed using the first and
second sealing members 201 and 202, a small leakage amount was
measured. Particularly, when the porosity of the second sealing
member 202 was 2.9%, which is relatively low, a relatively small
gas leakage amount was measured. On the other hand, in Comparative
Examples 1 and 2 in which the single-layered sealing member was
formed, a relatively larger gas leakage amount was measured
compared to Embodiments 1 and 2. In Comparative Example 2, the
sealing member was not formed due to poor workability.
[0045] While the present invention has been described in connection
with certain exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended
claims, and equivalents thereof.
* * * * *